This paper presents a static model of a one type of FES-TO electro-pneumatic proportional valves. This model will be used to design linear or nonlinear control strate-gy. The experimental characterization of pneumatic fluid power components, especially proportional valves and servo-valves are required when their behavior must be modeled. Since the technical specification from manufac-ture are, in general, insufficient, an experimental meas-urement is carried out. A simulation model using these experimental measurements is proposed. An approxima-tion of the mass flow stage characteristic of this five-way proportional valve is presented. This work is required to improve the performance of a mechanical simulator (BirthSIM) that is used to simulate labor during child-birth and to train students in the obstetrical art. BirthSIM is composed of a dynamic manikin simulating a pregnant human female and in witch a new-born head is located within a pelvis floor. The new-born head is connected with a pneumatic actuator driven by two ser-vodistributor FESTO. The objective of this research is to make BirthSIM work automatically, and to carry out the synthesis of the linear et nonlinear control laws in feed-back control in position or in force tracking according to desired trajectories.